太阳黑子周期与行星的引潮力

太阳黑子周期的复杂性增加了人们发现其规律的困难,本文对黑子长、短周期进行了统计分析,发现长周期存在7.1年、14.2年、21.3年、28.4年、42.6年的系列,短周期的时变性比长周期的更明显.对黑子周期的外部触发机制做了讨论,发现黑子周期与行星周期之间有良好的对应关系.     

用功率谱分析昆明地区6—9月气象要素场的振荡周期

本文通过对昆明地区30年的6～9月地面十四点气压场,温度场和湿度场的观测资料进行逐日功率谱分析,得出昆明地区上述要素场存在5～7d的周期振荡,从而为中短期天气预报提供客观依据.     

北京地区太阳黑子活动周期和年降水关系的初步研究

本文对北京地区太阳黑子活动周期与年降水量的变化关系，通过长系列（１８４１￣１９９２年）资料统计计算，初步探讨其规律性，根据实测资料统计结果，对太阳黑子活动与年降水量的组合关系，提出４个“型期”类型，可为进一步预测和建立数据模型打下基础，同时，亦可为北京地区进行年降水量的长期预报，提供统计数据。     

用数字信号处理方法分析太阳黑子活动的周期性

太阳黑子数是描述太阳活动水平的主要指标,太阳活动直接影响人类健康和人类赖以生存的环境—地球;依据数字信号处理原理,采用多种处理方法,分析处理了1770-1869年的太阳黑子数年均值;得出了太阳黑子存在11-12年周期的结论.结果表明该方法对研究太阳活动规律乃至天体规律是有效的.     

太阳黑子数与电离层TEC的相关性分析

为了研究电离层TEC与太阳黑子数在短周期上的相关关系,采用1997～2004年的太阳黑子数资料与同期厦门站的电离层TEC数据,利用小波功率谱分析的方法提取3个尺度的短周期,并利用小波相干谱的方法重点研究了两者在278 d周期上的相关性。研究表明：太阳黑子数和电离层TEC主要存在准27 d、准半年周期以及年周期等短周期,而且电离层TEC和太阳黑子在准27 d周期上有良好的相关性。位相计算表明,电离层TEC的变化滞后于太阳黑子数2～3 d。厦门地区TEC与太阳活动的相关性在夏季比其他季节更强,这对提高该地区电离层TEC预报精度有很大意义。     

周期振动信号测量优化方法的探讨

针对周期振动信号测量过程中受到的各种干扰,根据分析傅立叶变换和数字滤波器基本原理,选取FIR带通滤波器作为滤除干扰信号的方法.并通过实验比较该滤波方法的多种使用方案,结合对信号采集周期的选取提出了一种适合此类周期振动信号的最佳优化方法.实验结果表明,该方法能够成功提取有用信号,既保证数据的稳定性又提高了信号的测试效率.     

太阳黑子活动与大理紫外线强度的关系研究

利用2010年7月15日至2010年11月15日共5个月中每天的太阳黑子群总数的数据和大理地区的紫外线强度的数据对太阳黑子活动与大理紫外线强度的关系进行了研究。为了统计方便,规定紫外线强度"最弱、弱、中等、强、很强"分别用数字"1、2、3、4、5"代替。结果表明:黑子群总数是2时紫外线总是比较强,黑子群总数在一段时间(大约3 d以上)内持续为2时,之后总会出现紫外线极强的情况;当紫外线达到强或很强后会逐渐下降,此变化与黑子群总数变化无关。     

连续周期信号傅立叶变换的两种形式

连续周期信号的傅立叶变换实质上存在两种形式。由于第一种形式的物理意义较为明显,所以该种形式较为常用;第二种形式的优点在于揭示了非周期信号傅立叶变换和由该非周期信号周期延拓后所得周期信号的傅立叶变换的关系,经证明这两种形式实质上是相等的。     

伽利略对太阳黑子的发现和论证

伽利略用望远镜观测到太阳黑子的存在以后,又对黑子的性质做了细致分析,排除了它们是行星凌日造成的现象,从多个方面论证了它们是太阳表面的一部分,并由此得出了太阳本身也存在自转的结论.伽利略的这一工作是科学史上首次对太阳黑子做出的具有真正科学意义的研究,其结论向传统的天体完美宇宙论发起了挑战,给教会统治的天文学说的理论基础以...     

分数傅立叶变换(FrFT)在物体的横向位移和倾斜测量中的应用

分数傅立叶变换是光学信息处理中的较新的分支,而得到广泛的关注。本文利用其变换的特性,综合利用分数傅立叶变换和常规傅立叶变换,提出同时测量物体横向位移和测量的方法,并给出了实验的结果。     

双摆振动系统的同相振动性

采用MIRONENKO的反射函数法研究了双摆振动系统x′=A(t)x与y′=B(t)y的同相振动性,其中A(t)=(aij(t))2×2,B(t)=(bij(t))2×2.假设F(t),G(t)分别为x′=A(t)x,y′=B(t)y的反射矩阵,当A(t+2ω)=A(t),B(t+2ω)=B(t)时,矩阵F(-ω),G(-ω)分别相似于x′=A(t)x,y′=B(t)y的根本矩阵.若特征方程|λE-F(-ω)|=0与|μE-G(-ω)|=0具有相同的特征根,则x′=A(t)x与y′=B(t)y的稳定性相同.文中给出了特征方程|λE-F(-ω)|=0与|μE-G(-ω)|=0具有相同特征根的充分条件.     

Periodicity of sunspot activity in the modern solar cycles

Sunspot number, sunspot area and sunspot unit area are usually used to show sunspot activity. In this paper,periodicity of sunspot activity of modern solar cycles has been investigated through analyzing the monthly mean values of the three indices in the time interval of May 1874 to May 2004 by use of the wavelet transform. Their global power spectra and local power spectra are given while the statistical tests of these spectra are taken into account. The main results are (1) the local wavelet power spectrum of the sunspot number seems like that of the sunspot area, indicating that the periodicity of the both indices is similar. The local power spectrum of the sunspot unit area resembles the local power spectra of the previous two indices, but looks more complicated. (2) the possible periods in sunspot activity are about 10.6 (or 10.9 years for the sunspot unit area), 31,and 42 years, and the period of about 10.6 years is statistically significant in the considered time. For the periods of about 31 and 42 years, their power peaks are under the 95% confidence level line but over the mean red-noise spectral line, and for the other rest periods, their power peaks are even under the mean red-noise spectral line, which are statistically insignificant. (3) the local power of the three periods is higher in the late stage than in the early stage of the considered time. (4) the period characteristics of the three indices, shown in the global power spectra and the local power spectra, are similar but there is difference in detail.     

Wavelet analysis of sunspot relative numbers

The time series of the monthly smoothed sunspot numbers in 1749-2000 is analyzed with the wavelet.The result shows that besides the known time-variation of the period about 11 years, other main periods of the sunspot numbers, such as the periods of about 100 years and so on,vary with time. We suggest that the time-variation of the main periods is the manifestation of the complex variation of sunspot numbers. It is significant to make a thorough study of the character and mechanism of the time-variation of the periods for proving prediction of sunspot numbers, especially for understanding the variation process of sunspot numbers.     

联系离散Laplacian的半群上的振动算子

该文研究了联系离散Laplacian Δd的热半群上的振动算子O(Wt). 利用离散的半群方法和离散的向量值Calderón-Zygmund理论,证明了振动算子O(Wt)在1〈p〈∞时从p()到p()是有界的, 而且从1()到弱－1() 也是有界的.     

Time-variation of the near 5-month period of sunspot numbers

The variation of the near 5-month period of sunspot numbers is discussed on the basis of the wavelet transform of the daily sunspot number series in the 14th—22nd solar cycles. The result shows that the period exists in every cycle and its energy density (amplitude) is comparatively large in the peak section of the cycle. In the distinct cycle, the length and intensity of the period is different, which means that the period varies with time. The near 25-day period is also analyzed and it is found to be timevariable and even not very stable in the peak section of the cycle. The variations of the two periods show that the near 5-month period should not be simply regarded as the multiples of the near 25-day period.     

热声振荡的格子气模拟

采用二维九速的格子气模型模拟热声振荡,建立了完备的多体碰撞规则,提供了粘性和热边界的处理方法.对不同热源温度的热声振荡起振特性进行了模拟,同时也数值模拟研究了板叠两端温度随时间的响应过程.研究结果显示,碰撞规则完善与否会影响格子气的模拟结果,系统中的温度场对板叠温差的扰动存在响应滞后,温差直接影响热声振荡的起振特性.此外,低温热源对格子气模型噪声的影响更为敏感.     

滞后广义系统的平衡振荡

通过等价分解的方法,研究了滞后广义系统的平衡振荡问题,利用大系统分解法及Lyapunov方法对滞后广义系统进行分析,给出了滞后广义系统周期解的存在性、惟一性和稳定性的判据,拓宽了广义系统理论的研究领域。     

谐和与有界噪声激励下一个非线性电力系统的混沌振荡

研究了一个非线性电力系统在谐和与有界噪声激励下,系统出现混沌振荡的现象。从能量方面求出了该系统在均方意义下产生混沌的条件。     

Check of free oscillation signal with SG data

The observation of the Earth's free oscillation is an important way tostudy the Earth's inner structure and geophysical parameters. Many geophysicists have investigated the Earth's normal modes with strainmeters and spring gravimeters. Since the superconducting gravimeters appeared, people have gained a new kind of more stable instruments to detect the normal modes. The measurement for the Earth's free oscillation with the superconducting gravimeters is one of the main goals of the Global Geodynamics Project. In this note, we have investigatedthe Earth's normal modes excited by Peru Ms 7.9 Earthquake on June 23, 2001 with the superconducting gravimeter C032 at the Wuhan station. After having completed the subtraction of gravity tides with the 20th order polynomial fitting, and the correction for pressure and the analysis of the noise spectrum of the superconducting gravimeter, we accurately observed all base normal modes from 0S0 to 0S32 and the splittings of 0S2 and 0S3. Those results show a good agreement with the HB1 model.     

基于多元统计分析的通货膨胀水平的周期变动分析与综合测定

对通货膨胀的常用指标的周期变动及其综合测定进行探讨。首先利用多元逐步回归分析方法,建立了各物价指数的三角回归模型,进行了周期变动分析;然后利用因子分析法建立了通货膨胀水平的综合测定模型。文章对我国通货膨胀的变化状态作出了较好的分析。